Magneto



July 1935. L. P. KONGSTED 2,007,373

MAGNETO Filed NOV. 14, 1933 INVENTOR. 00707 Plfon arfied BY ATTORNEY.

lfa'tented July .9, 1935 UNITED STATES PATENT OFFICE MAGNETO Ludwig nxwted, 1m to United American Spring- Corporation, field, Mara, acorporation of New York ApplicationNovember 14, 193:, Serial 110.657,925 6 Claims. (cl. 171-252) This invention relates to. improvements inmag- .netos for the ignition systems of internal combustion engines andparticularly to a magneto of the so-called timer type which is similarin appearance to timer distributors now employed with battery ignitionsystems.

An object or the invention is to provide a magneto that is simple inconstruction, inexpensive to make, efllcient in operation and easy'toservice.

A further object of the invention is to providea ma neto in which thegenerating windings an s ationary and "which has a magnet structure toserve as the rotor, the latter preferably being made from a castmagnetic alloy of high coercive force. Thestator is laminated V andprovides cores for the generating coils, and the entire construction isassembled in a single housing which, contains also a circuit breaker anddistributor. The generating coils of the magneto are intended to beconnected to a separate ignition coil, the low tension circuit ofwhich-is periodicallyinter'rupted by the circuit breaker and the 'hightension circuit of which is controlled by the distributor in the usualway. These and other objects and advantages of the invention are madeclear in the ensuing description and the novel features are pointed outin the appended claims; but the right is of course reserved to makechanges in details of construction without departing from the principleof the invention.

On the drawing: Fig; 1 is an axial section through a according to thisinvention; Fig. 2 as section taken substantially on the line 2-2 in Fig.1; Fig. 3 is a top view of the magneto with the distributor' casingremoved showing the plan of a the circuit breaker; and Fig. 4 is adiagram of the circuits.

The houeing of the magneto-is made in two sections, the lower section Ibeing preferably of cast iron and the upper section 2.preferably ofdie-cast aluminum. Between them is the laminated annular stator 3surrounding therotor l with radial projections of alt rnating polarity.The rotor 4 is cast from cobal other magnetic material of high coerciveforce and is finished by grinding. Itis driven by a shaft 5 at the camshaft speed of a '4 .cycle engine and the upper and lower sections, 2and I respectively, are connected by a sleevefi of tubular sheet steelor brass which envlops the stator 3. The top of section 2 mounts thecircuit breaker, to be described-presently, and sup ports thedistributor cap I of insulation."

magneto:

magnet steel or The laminations of the stator 3 have internalprojections or teeth I forming polepieces for the generating eofls Q.The number of projections I and the number of magnet poles of the rotor'4 depend on the number, of cylinders of the engine for which themagneto is intended, in this case eight. The rotor, which has a centralhole at II for lightness, has on its upper and lower ends flanges IIheld together by rivets I 2 w means ofwhich the end flanges II arecaused 10 to grip the rotor 4 flrmly between them. Each flange isprovided with driving keys I3 of such size and shape that they flttightly between the projections of the rotor, so that when the lowerflange II is rotated the entire rotor is revolved. The two flanges IIare of non-magnetic material such as die-cast bronze, and the keys II,which are preferably four in number on each of these flanges, areintegral with the respective flanges. The lower end of sleeve 6 issecured to section I by means of screws I4 and to the section I byspinning the upper edge over a rib or shoulder II. e The lower section Iof the housing has a bearing. I for the drive shaft 5 and within sec--tion the shaft I carries a cup-shaped plate II to which is secured thegovernor weights I 8 on pivots I These weights are-each pivotallyconnected to studs 2! secured to the bottom flange II, the studs 2|being connected to the lower flange I I as indicated at 2| in anysuitable way. To receive the studs 2| the weights I8 may be slotted sothat when the weights are moved outward from the center by centrifugalforce the angular relation between the shaft 5 and rotor I is altered toadjust the time of the spark in the well known way. The upper end ofshaft 5 is providedhwith a ball bearing in the lower flange I I. Theupper flange II has a shaft'projection 23 in line with the shaft I andreceived in a ball bearing in section 2. The upper part of shaft 23passes through section 2 and carries the circuit breaker cam 24 and thedistributor rotor 25 of insulation.

The outer face of section 2 has a concave seat for acondenser 26 held bya clip 21, and carries the metalcircuit breaker lever 28 on an insulatedpivot 23. This lever has a rubbing block ll en-' gaging the cam 24, anda contact 3| engaging the: fixed contact 32. The coils 8 may beconnected in series'or parallel or series parallel with each other andone end of their circuit is connected by conductor 33 to binding post34, this conductor passing through a suitable opening in the top section2. Afllxed to the insulated binding post 55 for depriving the engine ofignition by grounding- 34 and to the end of the lever 28 is the circuitbreaker spring 35 and the conductor 38 leading to the insulated terminalof condens r 26. The

other end of the circuit of coils 9 is onnected by condenser 26 is alsogrounded on this section.

Hence whenever the contacts 3i and 32 engage each other the circuit ofthe coils 9 is complete. and when the contacts II and 32 are separatedthis circuit is broken.

The top of the section 2 has an outside shoulder 39 to receive the rimat the lower open end fo the distributor cap I, which has hightensionterminals 49 projecting inside thereof and enlarged at their outer endsto provide sockets 4| embedded in the bosses 42 of the cap for receivingtho sparkplug cables. The upper end of cap I is closed by a plate 43having a similar central boss 42 and socket 4|, the inner end of thisterminal carrying a brush 44 which contacts with a spring 45 secured tothe distributor terminal 46 and rotor 25 by rivet 41. The cam 24 has ahollow. projection 48, the outer end of which is counterbored at 49 toprovide a shouldef for screw 58 and lock washer. This screw enters athreaded bore in shaft 23 and, when tightened, holds the cam fast on theshaft. The rotor 25 is hollow to receive the projection 48 and is keyedto the projection on the cam as shown .at 5|.

The rims of the sections i and 2 of the housing are shouldered at 52 toprovied seats for the stator 3 and the end laminationsare thick, asshown at 53,};0 engage these seats.

The housing of .the magneto may have a hand lever 54 for manual timinginaddition to the governor adjustment.

In Fig. 4, the separate ignition coil is indicated with primary winding56 and secondary winding 51. One terminal of the primary is connected tothe binding post 34 and for this purpose the distributor cap may have anopening 55. The other /the other terminal is connected to the primary as'shown or separately therefrom if desired. The

circuit between the coils 9 and the-lever 28may include a hand switch 58mounted on the magneto in any suitable position, or a primary groundingswitch may be mounted at any convenient point on the engine orinstrument board terminal 34. Two generating coils 9 are shown inseries. r

' in each of the coils 9, which may therefore be connected in series orparallel combinations to give a suitable primary current for theseparate ignition coil. The interrupter 28 is opened successively at ornear the point of maximum cur-1' rent by the lobes on the ca'm 24. Theenergy stored in the magnetic field is prevented from forming adestructive arc at the'contact points 3l' and 32 by the condenser 26,the energy being quickly transferred to the primary winding 56 of theignition coil. The'rapid change of flux in the core caused by thebuilding up of the prima y current in winding 56 causes a high voltagetobe generated in the secondary 51 of sufficient intensity to produce agood hot spark at the spark- P u ingwindings 9 standard ignition coils,such as those now used for battery ignition systems, may be used withoutchange. This,\together with the simple construction of the timer, whichhas no high tension windings within it, makes this magneto an economicalunit to manufacture. By

1 using cast magnetic alloy having high coercive force, the rotor andthus the entire magneto is of suitable size and weight'for mounting on atimer shaft as shown- Though illustrated in Fig. 4 as connected acrossthe primary circuit, the breaker lever may also be in series with thecoils 9 and 56.

If desired, the projections of rotor 4 may have laminated pole-shoessecured to their ends in any suitable way. The principal advantage ofmaking the rotor in the shape of a casting resides in the large savingin the machining'operations, since all that.is

necessary is to assemble the cast -rotor and finish grinding it to theproper diameter. At least one magnetic alloy of, high coercive force isadapted for castings. The high coercive forcereferred to is of theorder, or higher than that, of 15% cobalt ma t steel.

Having thus described the invention, what is claimed is:

1. In a magneto of the timer type, a housing comprising upper and lowersections, a stator secured between said sections and bearing generatingfwindings, a rotor in the housing sur-' terminal carried thereby mountedupon said shaft projection to'be actuated by the rotor.

2. In a magneto of the timer type, a housing comprising upper and lowersections, a sleeve uniting said sections, a stator bearing generatingwindings secured between the sections, a rotorwithin the housingsurrounded by the stator, the

rotor having a shaft. projection-passing through.

one section, a cam and an insulated movable terminal mounted on saidshaft projection, a

circuit breaker. on the outer end of said section to be controlled bythe cam, an insulating distributor casing secured to said section, fixedter- 1 find that with the proper design of generatminals carried by saidsection in cooperative relation to said terminal; and a cap for saidcasing having a central terminal with a tip inside said casing and aspring attached to the movable terminal bearing upon said tip.

3. A magneto comprising a magnet member with polar projections, a flangesecured at each end of said magnet, a plurality of projecting keys onone of said flanges, said keys extending into apertures between saidpolar projections and establishing a firm driving connection therewith.

4. A magneto comprising a magnet member with polar projections, a flangesecured at each end of said magnet, and aplurality of integrally formedkeys on each flange, said keys extending into apertures between saidpolar projections and establishing a firm driving connection therewith.

5. A magneto comprising a magnet member having polar projections, aflange secured to said 8.0 am 3 magnet, and means for establishing afirm drivribs, a non-magnetic flange secured at each end ing connectionbetween said magnet and said flange, said means including a Projectingkey on said flanges and engaging said magnet said flange.

a firm driving connection is formed. 6. A magneto comprisingacylindricai magnet member having a plurality oi! radially projectingwhereby 5 LUDVIG P. KONGBTED.

of said magnet, a plurality of projecting keys on

